Modbus Interface Definitions (V3.0)

Solar Inverter

Modbus Interface Definitions (V3.0)

Issue 02

Date 2020-06-08

HUAWEI TECHNOLOGIES CO., LTD.

Copyright © Huawei Technologies Co., Ltd. 2020. All rights reserved.

No part of this document may be reproduced or transmitted in any form or by any means without priorwritten consent of Huawei Technologies Co., Ltd. Trademarks and Permissions

and other Huawei trademarks are trademarks of Huawei Technologies Co., Ltd.All other trademarks and trade names mentioned in this document are the property of their respectiveholders. NoticeThe purchased products, services and features are stipulated by the contract made between Huawei andthe customer. All or part of the products, services and features described in this document may not bewithin the purchase scope or the usage scope. Unless otherwise specified in the contract, all statements,information, and recommendations in this document are provided "AS IS" without warranties, guaranteesor representations of any kind, either express or implied.

The information in this document is subject to change without notice. Every effort has been made in thepreparation of this document to ensure accuracy of the contents, but all statements, information, andrecommendations in this document do not constitute a warranty of any kind, express or implied.

Huawei Technologies Co., Ltd.Address: Huawei Industrial Base

Bantian, LonggangShenzhen 518129People's Republic of China

Website: https://e.huawei.com

Issue 02 (2020-06-08) Copyright © Huawei Technologies Co., Ltd. i

https://e.huawei.com

Contents

1 Supported Models................................................................................................................... 11.1 Model Description................................................................................................................................................................... 1

2 Overview....................................................................................................................................62.1 Terms and Abbreviations...................................................................................................................................................... 6

3 Register Definitions.................................................................................................................8

4 Customized Interfaces..........................................................................................................234.1 Obtaining the System Information of Optimizers.....................................................................................................234.2 Obtaining Real-time Data of Optimizers..................................................................................................................... 24

5 Interface Instructions........................................................................................................... 285.1 Alarm Information................................................................................................................................................................ 285.2 Power Grid Scheduling........................................................................................................................................................ 315.2.1 cosφ-P/Pn Characteristic Curve.................................................................................................................................... 315.2.2 Q-U Characteristic Curve................................................................................................................................................ 325.2.3 PF-U Characteristic Curve............................................................................................................................................... 335.3 Grid Codes............................................................................................................................................................................... 345.4 Energy Storage Specifications...........................................................................................................................................44

6 Overview of the Communications Protocol.................................................................... 486.1 Physical Layer......................................................................................................................................................................... 486.2 Data Link Layer......................................................................................................................................................................486.2.1 Modbus-RTU....................................................................................................................................................................... 496.2.1.1 ADU Length......................................................................................................................................................................496.2.1.2 Communications Address............................................................................................................................................ 496.2.1.3 CRC...................................................................................................................................................................................... 506.2.2 Modbus-TCP........................................................................................................................................................................ 516.2.2.1 ADU Length......................................................................................................................................................................516.2.2.2 MBAP Packet Header.................................................................................................................................................... 516.2.2.3 Communications Address............................................................................................................................................ 526.2.2.4 TCP Port............................................................................................................................................................................. 536.2.2.5 TCP Link Establishment Process................................................................................................................................ 536.3 Application Layer.................................................................................................................................................................. 546.3.1 Function Code List.............................................................................................................................................................54

Solar InverterModbus Interface Definitions (V3.0) Contents

Issue 02 (2020-06-08) Copyright © Huawei Technologies Co., Ltd. ii

6.3.2 Exception Code List........................................................................................................................................................... 556.3.3 Reading Registers (0x03)................................................................................................................................................ 566.3.3.1 Frame Format of a Request from a Master Node.............................................................................................. 566.3.3.2 Frame Format of a Normal Response from a Slave Node.............................................................................. 566.3.3.3 Frame Format of an Abnormal Response from a Slave Node....................................................................... 566.3.3.4 Examples........................................................................................................................................................................... 576.3.4 Writing a Single Register (0x06).................................................................................................................................. 586.3.4.1 Frame Format of a Request from a Master Node.............................................................................................. 586.3.4.2 Frame Format of a Normal Response from a Slave Node.............................................................................. 586.3.4.3 Frame Format of an Abnormal Response from a Slave Node....................................................................... 596.3.4.4 Examples........................................................................................................................................................................... 596.3.5 Writing Multiple Registers (0x10)............................................................................................................................... 606.3.5.1 Frame Format of a Request from a Master Node.............................................................................................. 606.3.5.2 Frame Format of a Normal Response from a Slave Node.............................................................................. 616.3.5.3 Frame Format of an Abnormal Response from a Slave Node....................................................................... 616.3.5.4 Examples........................................................................................................................................................................... 616.3.6 Reading Device Identifiers (0x2B)............................................................................................................................... 636.3.6.1 Command for Querying Device Identifiers............................................................................................................646.3.6.2 Command for Querying a Device List.....................................................................................................................656.3.6.3 Device Description Definition.................................................................................................................................... 666.3.7 Huawei-defined Functions (0x41)............................................................................................................................... 676.3.7.1 Uploading Files............................................................................................................................................................... 676.3.7.1.1 Starting the Upload................................................................................................................................................... 686.3.7.1.2 Uploading Data........................................................................................................................................................... 696.3.7.1.3 Completing the Data Upload................................................................................................................................. 706.3.7.1.4 Timeout Processing.................................................................................................................................................... 71

Solar InverterModbus Interface Definitions (V3.0) Contents

Issue 02 (2020-06-08) Copyright © Huawei Technologies Co., Ltd. iii

1 Supported Models

This chapter describes the solar inverter models that use the Modbus protocol andthe earliest firmware version. When a host needs to connect to these solarinverters, ensure that the firmware version is correct.

1.1 Model Description

1.1 Model Description

Table 1-1 Supported models and firmware versions

Model Model ID Earliest Firm Version

SUN2000L-2KTL 305 SUN2000L V100R001C00

SUN2000-2KTL-L0 338 SUN2000L V100R001C00

SUN2000L-3KTL 304 SUN2000L V100R001C00

SUN2000L-3KTL-CN 310 SUN2000L V100R001C00

SUN2000L-3KTL-CN-4G 311 SUN2000L V100R001C00

SUN2000-3KTL-CNL0 334 SUN2000L V100R001C20

SUN2000-3KTL-L0 339 SUN2000L V100R001C00

SUN2000-3KTL-M0 410 SUN2000MA V100R001C00


SUN2000L-3.68KTL 303 SUN2000L V100R001C00

SUN2000-3.8KTL-USL0 318 SUN2000L V100R001C10


SUN2000L-4KTL 302 SUN2000L V100R001C00


Solar InverterModbus Interface Definitions (V3.0) 1 Supported Models

Issue 02 (2020-06-08) Copyright © Huawei Technologies Co., Ltd. 1




SUN2000-4KTL-L0 340 SUN2000L V100R001C00



SUN2000L-4.125KTL-JP 331 SUN2000L V100R001C12

SUN2000L-4.6KTL 301 SUN2000L V100R001C00

SUN2000L-4.95KTL-JP 330 SUN2000L V100R001C12

SUN2000-4.95KTL-JPL0 342 SUN2000L V100R001C20

SUN2000L-5KTL 300 SUN2000L V100R001C00



SUN2000-5KTL-USL0 315 SUN2000L V100R001C10



SUN2000-5KTL-L0 341 SUN2000L V100R001C00












SUN2000-8KTL 415 SUN2000MA V100R001C10













SUN2000-10KTL 416 SUN2000MA V100R001C10







SUN2000-12KTL 417 SUN2000MA V100R001C10












SUN2000-50KTL-JPM1 59 SUN2000 V300R001C00

SUN2000-50KTL-M0 50 SUN2000 V300R001C00


SUN2000-60KTL-M0 55 SUN2000 V300R001C00





SUN2000-63KTL-JPH0 76 SUN2000HA V200R001C00

SUN2000-65KTL-M0 46 SUN2000 V300R001C00

SUN2000-70KTL-INM0 48 SUN2000 V300R001C00

SUN2000-70KTL-C1 45 SUN2000 V300R001C00

SUN2000-75KTL-C1 56 SUN2000 V300R001C00

SUN2000-90KTL-H1 73 SUN2000HA V200R001C00

SUN2000-95KTL-INH0 74 SUN2000HA V200R001C00




SUN2000-100KTL-USH0 70 SUN2000HA V200R001C00




SUN2000-100KTL-M0 141 SUN2000 V500R001C00

SUN2000-100KTL-M1 142 SUN2000 V500R001C00

SUN2000-100KTL-INM0 143 SUN2000 V500R001C00


SUN2000-110KTL-M0 144 SUN2000 V500R001C00

SUN2000-125KTL-M0 145 SUN2000 V500R001C00








The maximum active power (Pmax), maximum reactive power (Qmax), and rated power (Pn)corresponding to each model can be obtained from the register interface. The model ID isthe unique code of the model.



2 Overview

Modbus is a widely used protocol for device communications. This documentdescribes the Modbus protocol used by Huawei solar inverters, and can be used toregulate follow-up third-party integrated development. Huawei solar inverterscomply with the standard Modbus protocol, and this document focuses on theinformation specific to Huawei solar inverters. For other information aboutModbus, see the standard documents about the Modbus protocol. For detailsabout the standard protocols used by Huawei solar inverters and customizedinteraction modes and examples, see chapter 6 Overview of theCommunications Protocol.

2.1 Terms and Abbreviations

2.1 Terms and Abbreviations

Table 2-1 Terms and abbreviations

Name Description

Master node During master-slave communication, the party thatinitiates a communication request is referred to asthe master node.

Slave node During master-slave communication, the party thatresponds to a communication request is referred toas the slave node.

Broadcast address Fixed to 0.

Register address A register address is recorded in two bytes.

U16 Unsigned integer (16 bits)

U32 Unsigned integer (32 bits)

I16 Signed integer (16 bits)

I32 Signed integer (32 bits)

STR Character string

Solar InverterModbus Interface Definitions (V3.0) 2 Overview


Name Description

MLD Multiple bytes

Bitfield16 16-bit data expressed by bit

Bitfield32 32-bit data expressed by bit

N/A Not applicable

s Second

Epoch seconds The number of seconds that have elapsed since1970-01-01 00:00:00

RO Data that is readable only

RW Data that is readable and writable

WO Data that is writable only

Solar InverterModbus Interface Definitions (V3.0) 2 Overview


3 Register Definitions

Table 3-1 Register definitions

No. SignalName

Read/Write

Type

Unit

Gain

Address

Quantity

Scope

1 Model RO STR N/A

1 30000

15 For details, see 1.1Model Description.

2 SN RO STR N/A

1 30015

10 N/A

3 PN RO STR N/A

1 30025

10 N/A

4 Model ID RO U16

N/A

1 30070

1 For details, see 1.1Model Description.

5 Number ofPV strings

RO U16

N/A

1 30071

1 N/A

6 Number ofMPP trackers

RO U16

N/A

1 30072

1 N/A

7 Rated power(Pn)

RO U32

kW 1000

30073

2 N/A

8 Maximumactive power(Pmax)

RO U32

kW 1000

30075

2 N/A

9 Maximumapparentpower (Smax)

RO U32

kVA

1000

30077

2 N/A

Solar InverterModbus Interface Definitions (V3.0) 3 Register Definitions


No. SignalName

Read/Write

Type

Unit

Gain

Address

Quantity

Scope

10 Maximumreactivepower (Qmax,fed to thepower grid)

RO I32 kVar

1000

30079

2 N/A

11 Maximumreactivepower (Qmax,absorbedfrom thepower grid)

RO I32 kVar

1000

30081

2 N/A

12 State 1 RO Bitfield16

N/A

1 32000

1 Bit 0: standbyBit 1: grid-connectedBit 2: grid-connectednormallyBit 3: grid connectionwith derating due topower rationingBit 4: grid connectionwith derating due tointernal causes of thesolar inverterBit 5: normal stopBit 6: stop due tofaultsBit 7: stop due topower rationingBit 8: shutdownBit 9: spot check


N/A

1 32002

1 Bit 0: locking status(0: locked; 1:unlocked)Bit 1: PV connectionstatus (0:disconnected; 1:connected)Bit 2: DSP datacollection (0: no; 1:yes)



No. SignalName

Read/Write

Type

Unit

Gain

Address

Quantity

Scope


N/A

1 32003

2 Bit 0: off-grid (0: on-grid; 1: off-grid)Bit 1: off-grid switch(0: disable; 1: enable)

15 Alarm 1 RO Bitfield16

N/A

1 32008

1 For details, see 5.1Alarm Information.


N/A

1 32009



N/A

1 32010


18 PV1 voltage RO I16 V 10 32016

1 A maximum of 24 PVstrings are supported.The number of PVstrings read by thehost is defined by theNumber of PV stringssignal. The voltageand current registeraddresses for each PVstring are as follows:

PVn voltage: 32014+ 2nPVn current: 32015+ 2nn indicates the PVstring number, whichranges from 1 to 24.

19 PV1 current RO I16 A 100 32017

1


1

21 PV2 current RO I16 A 100 32019

1


1

23 PV3 current RO I16 A 100 32021

1


1

25 PV4 current RO I16 A 100 32023

1

26 Input power RO I32 kW 1000

32064

2 N/A

27 Power gridvoltage/Linevoltagebetweenphases Aand B

RO U16

V 10 32066

1 When the outputmode is L/N, L1/L2/N,or L1/L2, Power gridvoltage is used.



No. SignalName

Read/Write

Type

Unit

Gain

Address

Quantity

Scope

28 Line voltagebetweenphases B andC

RO U16

V 10 32067

1 When the outputmode is L/N, L1/L2/N,or L1/L2, theinformation is invalid.

29 Line voltagebetweenphases C andA

RO U16

V 10 32068


30 Phase Avoltage

RO U16

V 10 32069


31 Phase Bvoltage

RO U16

V 10 32070


32 Phase Cvoltage

RO U16

V 10 32071


33 Power gridcurrent/Phase Acurrent

RO I32 A 1000

32072

2 When the outputmode is L/N, L1/L2/N,or L1/L2, Power gridcurrent is used.

34 Phase Bcurrent

RO I32 A 1000

32074


35 Phase Ccurrent

RO I32 A 1000

32076


36 Peak activepower ofcurrent day

RO I32 kW 1000

32078

2 N/A

37 Active power RO I32 kW 1000

32080

2 N/A

38 Reactivepower

RO I32 kVar

1000

32082

2 N/A



No. SignalName

Read/Write

Type

Unit

Gain

Address

Quantity

Scope

39 Power factor RO I16 N/A

1000

32084

1 N/A

40 Gridfrequency

RO U16

Hz 100 32085

1 N/A

41 Efficiency RO U16

% 100 32086

1 N/A

42 Internaltemperature

RO I16 °C 10 32087

1 N/A

43 Insulationresistance

RO U16

MΩ

1000

32088

1 N/A



No. SignalName

Read/Write

Type

Unit

Gain

Address

Quantity

Scope

44 Device status RO U16

N/A

1 32089

1 0x0000 Standby:initializing0x0001 Standby:detecting insulationresistance0x0002 Standby:detecting irradiation0x0003 Standby: driddetecting0x0100 Starting0x0200 On-grid(Off-grid mode:running)0x0201 Gridconnection: powerlimited(Off-grid mode:running: powerlimited)0x0202 Gridconnection: self-derating(Off-grid mode:running: self-derating)0x0300 Shutdown:fault0x0301 Shutdown:command0x0302 Shutdown:OVGR0x0303 Shutdown:communicationdisconnected0x0304 Shutdown:power limited0x0305 Shutdown:manual startuprequired0x0306 Shutdown: DCswitches disconnected0x0307 Shutdown:rapid cutoff



No. SignalName

Read/Write

Type

Unit

Gain

Address

Quantity

Scope

0x0308 Shutdown:input underpower0x0401 Gridscheduling: cosφ-Pcurve0x0402 Gridscheduling: Q-U curve0x0403 Gridscheduling: PF-U curve0x0404 Gridscheduling: drycontact0x0405 Gridscheduling: Q-P curve0x0500 Spot-checkready0x0501 Spot-checking0x0600 Inspecting0X0700 AFCI selfcheck0X0800 I-V scanning0X0900 DC inputdetection0X0A00 Running: off-grid charging0xA000 Standby: noirradiation

45 Fault code RO U16

N/A

1 32090

1 N/A

46 Startup time RO U32

N/A

1 32091

2 Epoch seconds, localtime

47 Shutdowntime

RO U32

N/A

1 32093

2 Epoch seconds, localtime

48 Accumulatedenergy yield

RO U32

kWh

100 32106

2 N/A

49 Daily energyyield

RO U32

kWh

100 32114

2 N/A



No. SignalName

Read/Write

Type

Unit

Gain

Address

Quantity

Scope

50 [Active]Adjustmentmode

RO U16

N/A

1 35300

1 0: percentage1: fixed valueNOTE

Addresses 35300 to35303 need to be readat a time.

51 [Active]Adjustmentvalue

RO U32

N/A

* 35302

2 Percentage: 0.1%Fixed value: 0.001 kWNote: For detailsabout the adjustmentvalue precision, seethe correspondingadjustment commandprecision.

52 [Active]Adjustmentcommand

RO U16

N/A

1 35303

1 40125: active powerderating bypercentage (0.1%)40120: active powerderating by fixedvalue40126: active powerderating by fixedvalue (W)42178: maximumactive power



No. SignalName

Read/Write

Type

Unit

Gain

Address

Quantity

Scope

53 [Reactive]Adjustmentmode

RO U16

N/A

1 35304

1 0: power factor1: absolute value2: Q/S3: Q-U characteristiccurve (command ID:0)4: cosφ-P/Pncharacteristic curve(command ID: 0)5: PF-U characteristiccurve (command ID:0)6: Q-P characteristiccurve (command ID:0)NOTE

Addresses 35304 to35306 need to be readat a time.

54 [Reactive]Adjustmentvalue

RO U32

N/A

* 35305

2 Power factor: 0.001Absolute value: 0.001kVarQ/S: 0.001Q-U characteristiccurve: 0cosφ-P/Pncharacteristic curve: 0PF-U characteristiccurve: 0Q-P characteristiccurve: 0

55 [Reactive]Adjustmentcommand

RO U16

N/A

1 35307

1 40122: power factor40123: Q/Sadjustment40129: reactive powercompensation at night(kVar)42809: reactive powerat night Q/S



No. SignalName

Read/Write

Type

Unit

Gain

Address

Quantity

Scope

56 [Energystorage unit1] Runningstatus*

RO U16

N/A

1 37000

1 0: offline1: standby2: running3: fault4: sleep mode

57 [Energystorage unit1] Chargeanddischargepower*

RO I32 W 1 37001

2 > 0: charging< 0: discharging

58 [Energystorage unit1] Current-day chargecapacity*

RO U32

kWh

100 37015

2 N/A

59 [Energystorage unit1] Current-daydischargecapacity*

RO U32

kWh

100 37017

2 N/A

60 [Powermetercollection]Activepower*

RO I32 W 1 37113

2 > 0: feeding power tothe power grid< 0: obtaining powerfrom the power grid

61 [Optimizer]Totalnumber ofoptimizers*

RO U16

N/A

1 37200

1 N/A

62 [Optimizer]Number ofonlineoptimizers*

RO U16

N/A

1 37201

1 N/A

63 [Optimizer]Feature data*

RO U16

N/A

1 37202

1 N/A



No. SignalName

Read/Write

Type

Unit

Gain

Address

Quantity

Scope

64 System time RW U32

N/A

1 40000

2 [946684800,3155759999]Epoch seconds, localtime

65 [Power gridscheduling]Q-Ucharacteristiccurve mode*

RW U16

N/A

1 40037

1 0: non-hysteresis1: hysteresis

66 [Power gridscheduling]Q-U dispatchtriggerpower (%)*

RW U16

% 1 40038

1 [0, 100]

67 [Power gridscheduling]Fixed activepowerderated

RW U16

kW 10 40120

1 Scope: [0, Pmax]

68 [Power gridscheduling]Reactivepowercompensation (PF)

RW I16 N/A

1000

40122

1 (–1, –0.8]U[0.8, 1]

69 [Power gridscheduling]Reactivepowercompensation (Q/S)

RW I16 N/A

1000

40123

1 [–1, 1]The device convertsthe value to a fixedvalue of Q for reactivepower control. Sindicates Smax.

70 [Power gridscheduling]Active powerpercentagederating(0.1%)

RW U16

% 10 40125

1 Scope: [0, 100]Interface for fineadjustment of activepower

71 [Power gridscheduling]Fixed activepowerderated (W)

RW U32

W 1 40126

2 Scope: [0, Pmax]



No. SignalName

Read/Write

Type

Unit

Gain

Address

Quantity

Scope

72 [Power gridscheduling]Reactivepowercompensation at night(kVar)

RW I32 kVar

1000

40129

2 [–Qmax, Qmax]

73 [Power gridscheduling]cosφ-P/Pncharacteristiccurve

RW MLD

N/A

1 40133

21 For details, see 5.2Power GridScheduling.

74 [Power gridscheduling]Q-Ucharacteristiccurve

RW MLD

N/A

1 40154


75 [Power gridscheduling]PF-Ucharacteristiccurve

RW MLD

N/A

1 40175


76 [Power gridscheduling]Reactivepoweradjustmenttime

RW U16

s 1 40196

1 [1, 120]. The defaultvalue is 10.

77 [Power gridscheduling]Q-U powerpercentageto exitscheduling*

RW U16

% 1 40198

1 [0, 100]

78 Startup WO

U16

N/A

1 40200

1 N/A

79 Shutdown WO

U16

N/A

1 40201

1 N/A

80 Grid code RW U16

NA 1 42000

1 For details, see 5.3Grid Codes.



No. SignalName

Read/Write

Type

Unit

Gain

Address

Quantity

Scope

81 [Power gridscheduling]Reactivepowerchangegradient

RW U32

%/s 1000

42015

2 [0.1, 1000]

82 [Power gridscheduling]Active powerchangegradient

RW U32

%/s 1000

42017

2 [0.1, 1000]

83 [Power gridscheduling]Scheduleinstructionvalidduration

RW U32

s 1 42019

2 [0, 86400]The value 0 indicatesthat the command isvalid permanently.

84 Time zone RW I16 min

1 43006

1 [–720, 840]

85 [Energystorage unit]Workingmode*

RW U16

N/A

1 47004

1 0: unlimited1: grid connectionwith zero power2: grid connectionwith limited power

86 [Energystorage unit]Time-of-useelectricityprice*

RW U16

N/A

1 47027

1 0: disable1: enable

87 [Energystorage unit]Time-of-useelectricitypriceperiods*

RW MLD

N/A

1 47028

41 For details, see 5.4Energy StorageSpecifications.

88 [Energystorage unit]LCOE*

RW U32

N/A

1000

47069

2 N/A



No. SignalName

Read/Write

Type

Unit

Gain

Address

Quantity

Scope

89 [Energystorage unit]Maximumchargingpower*

RW U32

W 1 47075

2 [0, Upper threshold]Default value: 3500

90 [Energystorage unit]Maximumdischargingpower*

RW U32

W 1 47077

2 [0, Upper threshold]Default value: 3500

91 [Energystorage unit]Power limitof the grid-tied point*

RW I32 W 1 47079

2 [0, Pmax]

Default value: Pmax

92 [Energystorage unit]Chargingcutoffcapacity*

RW U16

% 10 47081

1 [90, 100]Default value: 100

93 [Energystorage unit]Dischargecutoffcapacity*

RW U16

% 10 47082

1 [12, 20]Default value: 15

94 [Energystorage unit]Forcedcharging anddischargingperiod*

RW U16

min

1 47083

1 [0, 1440]The value is notstored.

95 [Energystorage unit]Forcedcharging anddischargingpower*

RW I32 W 1 47084

2 [–Max dischargingpower, Max chargingpower]Forced charging anddischarging power ≤Maximum chargingand discharging power≤ Rated charging anddischarging powerThe value is notstored.



No. SignalName

Read/Write

Type

Unit

Gain

Address

Quantity

Scope

96 [Energystorage unit]Fixedcharging anddischargingperiods*

RW MLD

N/A

1 47200

41 For details, see 5.4Energy StorageSpecifications.

NO TICE

Signals marked with * are supported only by certain models or standard codes.



4 Customized Interfaces

4.1 Obtaining the System Information of Optimizers

4.2 Obtaining Real-time Data of Optimizers

4.1 Obtaining the System Information of OptimizersData synchronization mechanism: The host is driven to refresh the systeminformation of optimizers by the change of the serial number (SN).

Synchronization process: For details, see 6.3.7.1 Uploading Files.

Data storage of the solar inverters: After the device search and positioning arecomplete, the record is updated. The record format is as follows:

File type: 0x45

Table 4-1 Record format

Data Length (Byte) Remarks

Format version 4 V101

SN 2 -

Length 2 -

Reserved 4 -

Number of optimizers 2 n, including the offlineoptimizers

Feature data ofoptimizer 1

78 -

Feature data ofoptimizer 2

78 -

... ... -

Solar InverterModbus Interface Definitions (V3.0) 4 Customized Interfaces



Feature data ofoptimizer n

78 -

Table 4-2 Feature data format (V101)


Optimizer address 2 Logical communicationaddress

Status 2 0: offline1: online

String number 2 -

Relative position of thePV string

2 1: near DC wiringterminals of the solarinverters

SN 20 -

Software version 30 -

Alias 20 -

4.2 Obtaining Real-time Data of OptimizersData synchronization mechanism: five-minute interval

Synchronization process: uploads the files and synchronizes data according to thetime period; uploads the most recent data if there is no filter condition. For details,see 6.3.7.1 Uploading Files.

Data storage: stores real-time data at five-minute intervals.

File type: 0x44

Table 4-3 Record format


File version 4 V101

Reserved 8 -

Optimizer data unit 1 N 12 + 26 x Number ofoptimizers

Optimizer data unit 2 N -




... - -

Optimizer data unit n N n indicates the numberof data records thatmeet the filter condition.Each piece of datacontains all optimizerdata for a time node.

Table 4-4 Data unit format (V101)


Time 4 Epoch seconds, localtime

Reserved 4 -

Length 2 -

Number of optimizers 2 -

Real-time data ofoptimizer 1

26 -

Real-time data ofoptimizer 2

26 -

... - -

Real-time data ofoptimizer n

26 n is the number ofoptimizers.

Table 4-5 Real-time data format


Optimizer address 2 Logical communication address

Output power 2 Gain: 10Unit: W

Voltage to ground 2 Gain: 10Unit: V




Alarm 4 Bit 00: abnormal PV module: inputovervoltageBit 01: abnormal PV module: inputundervoltageBit 02: abnormal PV module:output overvoltageBit 04: overtemperature alarm:overtemperatureBit 06: short circuit alarm: outputshort circuitBit 07: abnormal device: EEPROMfaultBit 08: abnormal device: internalhardware faultBit 09: abnormal device: abnormalvoltage to groundBit 10: abnormal communication:shutdown due to heartbeat timeout

Output voltage 2 Gain: 10Unit: V

Output current 2 Gain: 100Unit: A

Input voltage 2 Gain: 10Unit: V

Input current 2 Gain: 100Unit: A

Temperature 2 Gain: 10Unit: °C

Running status 2 0: offline1: standby2: locking3: faulty4: running5: pass-through6: inspecting7: escaping8: current limiting9: secure




Accumulated energyyield

4 Gain: 1000Unit: kWh



5 Interface Instructions

5.1 Alarm Information

5.2 Power Grid Scheduling

5.3 Grid Codes

5.4 Energy Storage Specifications

5.1 Alarm Information

Table 5-1 Alarm information

No. Alarm

Bit Alarm Name Alarm ID Level

1 Alarm1

0 High String Input Voltage 2001 Major

2 Alarm1

1 DC Arc Fault[1] 2002 Major

3 Alarm1

2 String Reverse Connection 2011 Major

4 Alarm1

3 String Current Backfeed 2012 Warning

5 Alarm1

4 Abnormal String Power 2013 Warning

6 Alarm1

5 AFCI Self-Check Fail.[1] 2021 Major

7 Alarm1

6 Phase Wire Short-Circuitedto PE

2031 Major

8 Alarm1

7 Grid Loss 2032 Major

Solar InverterModbus Interface Definitions (V3.0) 5 Interface Instructions


No. Alarm


9 Alarm1

8 Grid Undervoltage 2033 Major

10 Alarm1

9 Grid Overvoltage 2034 Major

11 Alarm1

10 Grid Volt. Imbalance 2035 Major

12 Alarm1

11 Grid Overfrequency 2036 Major

13 Alarm1

12 Grid Underfrequency 2037 Major

14 Alarm1

13 Unstable Grid Frequency 2038 Major

15 Alarm1

14 Output Overcurrent 2039 Major

16 Alarm1

15 Output DC ComponentOverhigh

2040 Major

17 Alarm2

0 Abnormal Residual Current 2051 Major

18 Alarm2

1 Abnormal Grounding 2061 Major

19 Alarm2

2 Low Insulation Resistance 2062 Major

20 Alarm2

3 Overtemperature 2063 Minor

21 Alarm2

4 Device Fault 2064 Major

22 Alarm2

5 Upgrade Failed or VersionMismatch

2065 Minor

23 Alarm2

6 License Expired 2066 Warning

24 Alarm2

7 Faulty Monitoring Unit 61440 Minor

25 Alarm2

8 Faulty Power Collector[2] 2067 Major

26 Alarm2

9 Battery abnormal 2068 Minor



No. Alarm


27 Alarm2

10 Active Islanding 2070 Major

28 Alarm2

11 Passive Islanding 2071 Major

29 Alarm2

12 Transient AC Overvoltage 2072 Major

30 Alarm2

13 Peripheral port shortcircuit[3]

2075 Warning

31 Alarm2

14 Churn output overload[4] 2077 Major

32 Alarm2

15 Abnormal PV moduleconfiguration

2080 Major

33 Alarm3

0 Optimizer fault[5] 2081 Warning

34 Alarm3

1 Built-in PID operationabnormal[6]

2085 Minor

35 Alarm3

2 High input string voltageto ground.

2014 Major

36 Alarm3

3 External Fan Abnormal 2086 Major

37 Alarm3

4 Battery ReverseConnection[7]

2069 Major

38 Alarm3

5 On-grid/Off-grid controllerabnormal[4]

2082 Major

39 Alarm3

6 PV String Loss 2015 Warning

40 Alarm3

7 Internal Fan Abnormal 2087 Major

41 Alarm3

8 DC Protection UnitAbnormal[8]

2088 Major



NO TICE

The preceding table lists the alarm information about Huawei solar inverters.Some alarms can be detected only after corresponding functional modules areconfigured.[1] AFCI functional unit[2] Power collector or power meter connected to the solar inverters[3] Detection of the external ports of the solar inverters that provide the 12 Vpower supply[4] This item can be detected when a built-in or external on-grid/off-gridfunctional unit is configured.[5] This item can be detected when optimizers are configured on the DC side.[6] This item can be detected when the solar inverters are configured with PIDfunctional units.[7] This item can be detected when energy storage units (ESUs) are configured.[8] Some models have DC protection units.

5.2 Power Grid SchedulingThis section describes the curve configuration format and precautions for powergrid scheduling by curve.

5.2.1 cosφ-P/Pn Characteristic Curve

Table 5-2 cosφ-P/Pn characteristic curve definition

Description DataType

Gain Unit Value Range

Number of points U16 1 N/A [2, 10]

P/Pn value at point 1 U16 10 % [0, 100]

cosφ value at point 1 I16 1000 N/A (–1, –0.8]U[0.8, 1]















P/Pn value at point 7 U16 10 % [0,100]

cosφ value at point 7 I16 1000 N/A (–1,–0.8]U[0.8,1]







5.2.2 Q-U Characteristic CurveTable2 Q-U Characteristic Curve definition




U/Un value at point 1 U16 10 % [80, 136]

Q/S value at point 1 I16 1000 N/A [–0.6, 0.6]























NO TICE

In Italian standards, this curve may be used together with the Q-U characteristiccurve mode, Q-U dispatch trigger power (%), and Q-U power percentage toexit scheduling parameters.

5.2.3 PF-U Characteristic CurveTable3 PF-U Characteristic Curve definition





PF value at point 1 I16 1000 N/A (–1, –0.8]U[0.8, 1]























5.3 Grid Codes

Table 5-3 List of grid codes

No. Standard Applicable Country orRegion

0 VDE-AR-N-4105 Germany

1 NB/T 32004 China

2 UTE C 15-712-1(A) France

3 UTE C 15-712-1(B) France

4 UTE C 15-712-1(C) France

5 VDE 0126-1-1-BU Bulgaria

6 VDE 0126-1-1-GR(A) Greece

7 VDE 0126-1-1-GR(B) Greece

8 BDEW-MV Germany

9 G59-England UK

10 G59-Scotland UK

11 G83-England UK

12 G83-Scotland UK




13 CEI0-21 Italy

14 EN50438-CZ Czech Republic

15 RD1699/661 Spain

16 RD1699/661-MV480 Spain

17 EN50438-NL Netherlands

18 C10/11 Belgium

19 AS4777 Australia

20 IEC61727 General

21 Custom (50 Hz) Custom

22 Custom (60 Hz) Custom

23 CEI0-16 Italy

24 CHINA-MV480 China

25 CHINA-MV China

26 TAI-PEA Thailand

27 TAI-MEA Thailand

28 BDEW-MV480 Germany

29 Custom MV480 (50 Hz) Custom

30 Custom MV480 (60 Hz) Custom

31 G59-England-MV480 UK

32 IEC61727-MV480 General

33 UTE C 15-712-1-MV480 France

34 TAI-PEA-MV480 Thailand

35 TAI-MEA-MV480 Thailand

36 EN50438-DK-MV480 Denmark

37 Japan standard (50 Hz) Japan

38 Japan standard (60 Hz) Japan

39 EN50438-TR-MV480 Turkey

40 EN50438-TR Turkey

41 C11/C10-MV480 Belgium




42 Philippines Philippines

43 Philippines-MV480 Philippines

44 AS4777-MV480 Australia

45 NRS-097-2-1 South Africa

46 NRS-097-2-1-MV480 South Africa

47 KOREA South Korea

48 IEEE 1547-MV480 USA

49 IEC61727-60Hz General

50 IEC61727-60Hz-MV480 General

51 CHINA_MV500 China

52 ANRE Romania

53 ANRE-MV480 Romania

54 ELECTRIC RULE NO.21-MV480

California, USA

55 HECO-MV480 Hawaii, USA

56 PRC_024_Eastern-MV480 Eastern USA

57 PRC_024_Western-MV480

Western USA

58 PRC_024_Quebec-MV480 Quebec, Canada

59 PRC_024_ERCOT-MV480 Texas, USA

60 PO12.3-MV480 Spain

61 EN50438_IE-MV480 Ireland

62 EN50438_IE Ireland

63 IEEE 1547a-MV480 USA

64 Japan standard(MV420-50 Hz)

Japan


Japan


Japan


Japan




68 IEC61727-50Hz-MV500 General

70 CEI0-16-MV480 Italy

71 PO12.3 Spain


Japan


Japan


75 KOREA-MV480 South Korea

76 Egypt ETEC Egypt

77 Egypt ETEC-MV480 Egypt

78 CHINA_MV800 China

79 IEEE 1547-MV600 USA


California, USA




Western USA




87 EN50549-LV Ireland

88 EN50549-MV480 Ireland

89 Jordan-Transmission Jordan

90 Jordan-Transmission-MV480

Jordan

91 NAMIBIA Namibia

92 ABNT NBR 16149 Brazil

93 ABNT NBR 16149-MV480

Brazil

94 SA_RPPs South Africa




95 SA_RPPs-MV480 South Africa

96 INDIA India

97 INDIA-MV500 India

98 ZAMBIA Zambia

99 ZAMBIA-MV480 Zambia

100 Chile Chile

101 Chile-MV480 Chile

102 CHINA-MV500-STD China

103 CHINA-MV480-STD China

104 Mexico-MV480 Mexico

105 Malaysian Malaysia

106 Malaysian-MV480 Malaysia

107 KENYA_ETHIOPIA East Africa

108 KENYA_ETHIOPIA-MV480

East Africa

109 G59-England-MV800 UK

110 NIGERIA Nigeria

111 NIGERIA-MV480 Nigeria

112 DUBAI Dubai

113 DUBAI-MV480 Dubai

114 Northern Ireland Northern Ireland

115 Northern Ireland-MV480 Northern Ireland

116 Cameroon Cameroon

117 Cameroon-MV480 Cameroon

118 Jordan-Distribution Jordan

119 Jordan-Distribution-MV480

Jordan

120 Custom MV600-50 Hz Custom

121 AS4777-MV800 Australia

122 INDIA-MV800 India




123 IEC61727-MV800 General

124 BDEW-MV800 Germany

125 ABNT NBR 16149-MV800

Brazil

126 UTE C 15-712-1-MV800 France

127 Chile-MV800 Chile


129 EN50438-TR-MV800 Turkey

130 TAI-PEA-MV800 Thailand

131 Philippines-MV800 Philippines

132 Malaysian-MV800 Malaysia

133 NRS-097-2-1-MV800 South Africa

134 SA_RPPs-MV800 South Africa

135 Jordan-Transmission-MV800

Jordan

136 Jordan-Distribution-MV800

Jordan

137 Egypt ETEC-MV800 Egypt

138 DUBAI-MV800 Dubai

139 SAUDI-MV800 Saudi Arabia

140 EN50438_IE-MV800 Ireland

141 EN50549-MV800 Ireland

142 Northern Ireland-MV800 Northern Ireland


144 IEC 61727-MV800-60Hz General

145 NAMIBIA_MV480 Namibia

146 Japan (LV202-50 Hz) Japan

147 Japan (LV202-60 Hz) Japan

148 Pakistan-MV800 Pakistan

149 BRASIL-ANEEL-MV800 Brazil

150 Israel-MV800 Israel





152 ZAMBIA-MV800 Zambia

153 KENYA_ETHIOPIA-MV800

East Africa

154 NAMIBIA_MV800 Namibia

155 Cameroon-MV800 Cameroon

156 NIGERIA-MV800 Nigeria

157 ABUDHABI-MV800 Abu Dhabi

158 LEBANON Lebanon

159 LEBANON-MV480 Lebanon

160 LEBANON-MV800 Lebanon

161 ARGENTINA-MV800 Argentina


163 Jordan-Transmission-HV Jordan

164 Jordan-Transmission-HV480

Jordan

165 Jordan-Transmission-HV800

Jordan

166 TUNISIA Tunisia

167 TUNISIA-MV480 Tunisia

168 TUNISIA-MV800 Tunisia

169 JAMAICA-MV800 Jamaica

170 AUSTRALIA-NER Australia

171 AUSTRALIA-NER-MV480 Australia

172 AUSTRALIA-NER-MV800 Australia

173 SAUDI Saudi Arabia

174 SAUDI-MV480 Saudi Arabia

175 Ghana-MV480 Ghana

176 Israel Israel

177 Israel-MV480 Israel

178 Chile-PMGD Chile




179 Chile-PMGD-MV480 Chile

180 VDE-AR-N4120-HV Germany

181 VDE-AR-N4120-HV480 Germany

182 VDE-AR-N4120-HV800 Germany

183 IEEE 1547-MV800 USA

184 Nicaragua-MV800 Nicaragua



California, USA




Western USA



192 Custom-MV800-50Hz Custom

193 RD1699/661-MV800 Spain

194 PO12.3-MV800 Spain


196 Vietnam-MV800 Vietnam

197 CHINA-LV220/380 China

198 SVG-LV Dedicated

199 Vietnam Vietnam

200 Vietnam-MV480 Vietnam

201 Chile-PMGD-MV800 Chile

202 Ghana-MV800 Ghana

203 TAIPOWER Taiwan

204 TAIPOWER-MV480 Taiwan

205 TAIPOWER-MV800 Taiwan

206 IEEE 1547-LV208 USA




207 IEEE 1547-LV240 USA

208 IEEE 1547a-LV208 USA

209 IEEE 1547a-LV240 USA

210 ELECTRIC RULE NO.21-LV208

USA

211 ELECTRIC RULE NO.21-LV240

USA

212 HECO-O+M+H-LV208 USA

213 HECO-O+M+H-LV240 USA

214 PRC_024_Eastern-LV208 USA

215 PRC_024_Eastern-LV240 USA

216 PRC_024_Western-LV208 USA

217 PRC_024_Western-LV240 USA

218 PRC_024_ERCOT-LV208 USA

219 PRC_024_ERCOT-LV240 USA

220 PRC_024_Quebec-LV208 USA

221 PRC_024_Quebec-LV240 USA


223 Oman Oman

224 Oman-MV480 Oman

225 Oman-MV800 Oman

226 Kuwait Kuwait

227 Kuwait-MV480 Kuwait

228 Kuwait-MV800 Kuwait

229 Bangladesh Bangladesh

230 Bangladesh-MV480 Bangladesh

231 Bangladesh-MV800 Bangladesh

232 Chile-Net_Billing Chile

233 EN50438-NL-MV480 Netherlands

234 Bahrain Bahrain




235 Bahrain-MV480 Bahrain

236 Bahrain-MV800 Bahrain

238 Japan-MV550-50Hz Japan

239 Japan-MV550-60Hz Japan

241 ARGENTINA Argentina

242 KAZAKHSTAN-MV800 Kazakhstan

243 Mauritius Mauritius

244 Mauritius-MV480 Mauritius

245 Mauritius-MV800 Mauritius

246 Oman-PDO-MV800 Oman

247 EN50438-SE Sweden

248 TAI-MEA-MV800 Thailand

249 Pakistan Pakistan

250 Pakistan-MV480 Pakistan

251 PORTUGAL-MV800 Portugal

252 HECO-L+M-LV208 USA

253 HECO-L+M-LV240 USA

254 C10/11-MV800 Belgium

255 Austria Austria

256 Austria-MV480 Austria

257 G98 UK

258 G99-TYPEA-LV UK

259 G99-TYPEB-LV UK

260 G99-TYPEB-HV UK

261 G99-TYPEB-HV-MV480 UK

262 G99-TYPEB-HV-MV800 UK

263 G99-TYPEC-HV-MV800 UK

264 G99-TYPED-MV800 UK

265 G99-TYPEA-HV UK




266 CEA-MV800 India

267 EN50549-MV400 Europe

268 VDE-AR-N4110 Germany

269 VDE-AR-N4110-MV480 Germany

270 VDE-AR-N4110-MV800 Germany

271 Panama-MV800 Panama

272 North Macedonia-MV800

North Macedonia

273 NTS Spain

274 NTS-MV480 Spain

275 NTS-MV800 Spain

NO TICE

Set the grid code based on local laws and regulations.

5.4 Energy Storage Specifications

Table 5-4 Format description of parameters for time-of-use electricity priceperiods

Description Data Type Gain Unit Value Range

Number of periods U16 1 N/A [0, 10]

Start time of period 1 U16 1 min [0, 1440]. The valueis the elapsedminutes since 00:00a.m. The start timeshould be earlierthan the end time.

End time of period 1 U16 1 min [0, 1440]. The valueis the elapsedminutes since 00:00a.m. The start timeshould be earlierthan the end time.




Electricity price inperiod 1

U32 1000 N/A N/A

Start time of period 2 U16 1 min [0, 1440]. The valueis the elapsedminutes since 00:00a.m. The start timeshould be earlierthan the end time.



U32 1000 N/A N/A

... ... ... ... ...

Start time of period10

U16 1 min [0, 1440]. The valueis the elapsedminutes since 00:00a.m. The start timeshould be earlierthan the end time.

End time of period10



U32 1000 N/A N/A

Table 5-5 Format description of parameters for fixed charging and dischargingperiods


Number of periods U16 1 N/A [0, 10]







Charging anddischarging power inperiod 1

I32 1 W [Discharging powerlimit, Chargingpower limit]. Fordetails, see thedescription of thesupported model.






... ... ... ... ...






End time of period10






6 Overview of the CommunicationsProtocol

The Modbus communications protocol consists of the following layers.

Figure 6-1 Modbus protocol layers

6.1 Physical Layer

6.2 Data Link Layer

6.3 Application Layer

6.1 Physical LayerHuawei solar inverters provide Modbus communication based on physical mediasuch as MBUS, RS485, WLAN, FE, and 4G. MBUS and RS485 comply with theModbus-RTU format. The communication through the WLAN, FE, and 4G media isbased on the TCP link and complies with the Modbus-TCP format.

6.2 Data Link LayerThe following figure shows the generic frame structure of the Modbus protocol.

Solar InverterModbus Interface Definitions (V3.0) 6 Overview of the Communications Protocol


Figure 6-2 Modbus generic frame format

6.2.1 Modbus-RTU

Figure 6-3 Modbus-RTU frame format

6.2.1.1 ADU Length

The application data unit (ADU) consists of 256 bytes based on the serial bus.

1. Slave address: 1 byte2. Cyclic redundancy check (CRC): 2 bytes3. PDU: 253 bytes

6.2.1.2 Communications Address

As shown in the figure below, Modbus-RTU is usually used for serialcommunication. Slave address represents the address of a slave solar inverter. Theaddress range is allocated as follows:

Figure 6-4 Modbus generic frame format

Table 6-1 Serial link address allocation

Broadcast Address Slave Node Address Reserved Address

0 1–247 248–255



Reserved addresses are used for access control of the communication extensionmodules. Huawei reserves the right to allocate the reserved addresses.

6.2.1.3 CRC

CRC applies to all bytes in front of the CRC code, which consists of 16 bits. Thereference code is as follows:

static unsigned char auchCRCHi[] = { 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40 } ; /*CRC values for the low-order byte*/ static char auchCRCLo[] = { 0x00, 0xC0, 0xC1, 0x01, 0xC3, 0x03, 0x02, 0xC2, 0xC6, 0x06, 0x07, 0xC7, 0x05, 0xC5, 0xC4, 0x04, 0xCC, 0x0C, 0x0D, 0xCD, 0x0F, 0xCF, 0xCE, 0x0E, 0x0A, 0xCA, 0xCB, 0x0B, 0xC9, 0x09, 0x08, 0xC8, 0xD8, 0x18, 0x19, 0xD9, 0x1B, 0xDB, 0xDA, 0x1A, 0x1E, 0xDE, 0xDF, 0x1F, 0xDD, 0x1D, 0x1C, 0xDC, 0x14, 0xD4, 0xD5, 0x15, 0xD7, 0x17, 0x16, 0xD6, 0xD2, 0x12, 0x13, 0xD3, 0x11, 0xD1, 0xD0, 0x10, 0xF0, 0x30, 0x31, 0xF1, 0x33, 0xF3, 0xF2, 0x32, 0x36, 0xF6, 0xF7, 0x37, 0xF5, 0x35, 0x34, 0xF4, 0x3C, 0xFC, 0xFD, 0x3D, 0xFF, 0x3F, 0x3E, 0xFE, 0xFA, 0x3A, 0x3B, 0xFB, 0x39, 0xF9, 0xF8, 0x38, 0x28, 0xE8, 0xE9, 0x29, 0xEB, 0x2B, 0x2A, 0xEA, 0xEE, 0x2E, 0x2F, 0xEF, 0x2D, 0xED, 0xEC, 0x2C, 0xE4, 0x24, 0x25, 0xE5, 0x27, 0xE7, 0xE6, 0x26, 0x22, 0xE2, 0xE3, 0x23, 0xE1, 0x21, 0x20, 0xE0, 0xA0, 0x60, 0x61, 0xA1, 0x63, 0xA3, 0xA2, 0x62, 0x66, 0xA6, 0xA7, 0x67, 0xA5, 0x65, 0x64, 0xA4, 0x6C, 0xAC, 0xAD, 0x6D, 0xAF, 0x6F, 0x6E, 0xAE, 0xAA, 0x6A, 0x6B, 0xAB, 0x69, 0xA9, 0xA8, 0x68, 0x78, 0xB8, 0xB9, 0x79, 0xBB, 0x7B, 0x7A, 0xBA, 0xBE, 0x7E, 0x7F, 0xBF, 0x7D, 0xBD, 0xBC, 0x7C, 0xB4, 0x74, 0x75, 0xB5, 0x77, 0xB7, 0xB6, 0x76, 0x72, 0xB2, 0xB3, 0x73, 0xB1, 0x71, 0x70, 0xB0, 0x50, 0x90, 0x91, 0x51, 0x93, 0x53, 0x52, 0x92, 0x96, 0x56, 0x57, 0x97, 0x55, 0x95, 0x94, 0x54, 0x9C, 0x5C, 0x5D, 0x9D, 0x5F, 0x9F, 0x9E, 0x5E, 0x5A, 0x9A, 0x9B, 0x5B, 0x99, 0x59, 0x58, 0x98, 0x88, 0x48, 0x49, 0x89, 0x4B, 0x8B, 0x8A, 0x4A, 0x4E, 0x8E, 0x8F, 0x4F, 0x8D, 0x4D, 0x4C, 0x8C, 0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86, 0x82, 0x42, 0x43, 0x83, 0x41, 0x81, 0x80, 0x40 }; unsigned short CRC16 ( puchMsg, usDataLen ) /* The function returns the CRC as a unsigned short type */ unsigned char *puchMsg ; /* message to calculate CRC upon */ unsigned short usDataLen ; /* quantity of bytes in message */ { unsigned char uchCRCHi = 0xFF ; /* high byte of CRC initialized */ unsigned char uchCRCLo = 0xFF ; /* low byte of CRC initialized */ unsigned uIndex ; /* will index into CRC lookup table */ while (usDataLen--) /* pass through message buffer */ { uIndex = uchCRCLo ^ *puchMsg++ ; /* calculate the CRC */ uchCRCLo = uchCRCHi ^ auchCRCHi[uIndex] ; uchCRCHi = auchCRCLo[uIndex] ; } return (uchCRCHi << 8 | uchCRCLo) ; }

Code source: MODBUS over Serial Line Specification and Implementation GuideV1.02



6.2.2 Modbus-TCP

Figure 6-5 Modbus-TCP frame format

6.2.2.1 ADU LengthThe recommended frame length is 260 bytes based on the standard. When someextended functions are applied, the data service provider may extend the ADU toa proper length based on the resources it possesses, to improve networktransmission efficiency. The ADU length is indicated by the length field in theMBAP packet header.

6.2.2.2 MBAP Packet HeaderIf Modbus is applied to TCP/IP, a dedicated MBAP packet header (Modbusapplication protocol packet header) is used to identify the Modbus ADU. TheModbus packet header consists of four fields and seven bytes, which are definedas follows.

Table 6-2 MBAP definition

Data Field Length(Byte)

Description Client Server

Transmission identifier

2 Matchingidentifier betweena request frameand a responseframe

Assigned bythe client;better beunique foreach dataframe

The identifierof theresponseframe fromthe servermust beconsistentwith that ofthe requestframe.




Description Client Server

Protocoltype

2 0 = Modbusprotocol

Assigned bythe client; 0 bydefault


Data length 2 Follow-up datalength

Assigned bythe clientbased on theactual dataframe

Assigned bythe serverbased on theactual framelength

Logicaldevice ID

1 0 Assigned bythe clientbased on theactual dataframe request


6.2.2.3 Communications AddressBased on the TCP communications host, unit 0 is used by default to access thedirectly connected slave node, and other addresses are used to access thedownstream devices of the slave node. The default address of the slave node is 0.The address is adjustable.



Figure 6-6 Communications address of the three-layer object structure

6.2.2.4 TCP PortIn a local area network or VPN environment, the master node may actively initiateTCP socket link establishment to the slave node. The master node can use the 502port to request data services from the slave node.

In a non-VPN environment across the public network, the device deployed on theinternal network needs to initiate TCP socket link establishment to the masternode exposed on the public network. In this case, you need to preset the fixedaccess port number of the master node on the slave node. To ensure security andreduce traffic, the master node must provide at least one encrypted port and onenon-encrypted port.

6.2.2.5 TCP Link Establishment ProcessThis section focuses on the cross-public network application.

The following figure shows the process of connecting a slave node.



Figure 6-7 Process of establishing a secure TCP connection

6.3 Application Layer

6.3.1 Function Code List

Table 6-3 Function code list

Function Code Meaning Remarks

0x03 Read registers. Continuously reads asingle register ormultiple registers.

0x06 Write a single register. Writes into a singleregister.

0x10 Write multiple registers. Continuously writes intomultiple registers.



6.3.2 Exception Code ListThe exception codes must be unique for each network element (NE) type. Thenames and descriptions should be provided in both the Chinese and English NEinterface document. Different versions of the same NE type must be backwardcompatible. Exception codes in use cannot be assigned to other exceptions.

Table 6-4 Exception codes returned by an NE (0x00–0x8F are for commonexception codes)

Code Name Description

0x01 Illegal function The function code received in the query is not anallowable action for the server (or slave node).This may be because the function code is onlyapplicable to newer devices, and was notimplemented in the unit selected. It could alsoindicate that the server (or slave node) is in thewrong state to process a request of this type, forexample because it is not configured and is beingasked to return register values.

0x02 Illegal dataaddress

The data address received in the query is not anallowable address for the server. Morespecifically, the combination of reference numberand transfer length is invalid. For a controllerwith 100 registers, the PDU addresses the firstregister as 0, and the last one as 99. If a requestis submitted with a starting register address of96 and a quantity of registers of 4, then thisrequest will successfully operate (address-wise atleast) on registers 96, 97, 98, 99. If a request issubmitted with a starting register address of 96and a quantity of registers of 5, then this requestwill fail with Exception Code 0x02 "Illegal DataAddress" since it attempts to operate on registers96, 97, 98, 99 and 100, and there is no registerwith address 100.

0x03 Illegal datavalue

The value contained in the query data field is notan allowable value for the server (or slave). Thevalue indicates a fault in the structure of theremainder of a complex request, such as anincorrectly implied length. It specifically does notmean that a data item submitted for storage in aregister has a value outside the expectation ofthe application program since the Modbusprotocol is unaware of the significance of anyparticular value of any particular register.

0x04 Slave nodefailure

An error occurred while the server wasattempting to perform the requested action.



Code Name Description

0x06 Slave devicebusy

The server cannot accept a Modbus request PDU.A client application determines whether andwhen to resend the request.

0x80 No permission An operation is not allowed because of apermission authentication failure or permissionexpiration.

6.3.3 Reading Registers (0x03)

6.3.3.1 Frame Format of a Request from a Master Node

Data Field Length (Byte) Description

Function code 1 0x03

Register start address 2 0x0000–0xFFFF

Number of registers 2 1–125

6.3.3.2 Frame Format of a Normal Response from a Slave Node



Number of bytes 1 2 x N

Register value 2 x N N/A

N refers to the number of registers.

6.3.3.3 Frame Format of an Abnormal Response from a Slave Node



Exception code 1 See 6.3.2 ExceptionCode List.



6.3.3.4 Examples

This section takes the Modbus-TCP communications frames as an example. Thedifferences between Modbus-RTU and Modbus-TCP lie in the additional addressfield and the CRC. Pay attention to the differences when using the Modbus-RTUframes. This also works for the follow-up examples.

The master node sends a query request (register address: 32306/0X7E32) to theslave node (logical device ID: 00).

Description Frame Data

MBAP header Protocol identifier 00

01

Protocol type 00

00

Data length 00

06

Logical device ID 00

Function code 03

Data Register address 7E

32

Number ofregisters

00

02

Normal response from the slave node



01

Protocol type 00

00

Data length 00

07


Function code 03

Data Number of bytes 04




Register data 00

00

00

01

Abnormal response from the slave node

Description Frame data


01

Protocol type 00

00

Data length 00

03


Function code 83

Data Error code 03

6.3.4 Writing a Single Register (0x06)




Register address 2 0x0000–0xFFFF

Register value 2 0x0000–0xFFFF








Register value 2 0x0000–0xFFFF





6.3.4.4 Examples

A master node sends a command (register address: 40200/0X9D08) to a slavenode (address: 00).

Description Frame data


01

Protocol type 00

00

Data length 00

06


Function code 06

Data Register address 9D

08

Register data 00

00







01

Protocol type 00

00

Data length 00

06


Function code 06

Data Register address 9D

08

Register data 00

00




01

Protocol type 00

00

Data length 00

03


Function code 86

Data Error code 04

6.3.5 Writing Multiple Registers (0x10)







Register start address 2 0x0000–0xFFFF

Number of registers 2 0x0000–0x007b

Number of bytes 1 2 x N

Register value 2 x N Value

N refers to the number of registers.





Number of registers 2 0x0000–0x007b





6.3.5.4 Examples

The master node sets the register address 40118/0X9CB6 to 2 and the registeraddress 40119/0X9CB7 to 50 for the slave node (address: 00). The request frameformat is as follows.



01

Protocol type 00

00

Data length 00




0B


Function code 10

Data Register address 9C

B6

Number ofregisters

00

02

Number of bytes 04

Register data 00

02

00

32




01

Protocol type 00

00

Data length 00

06


Function code 10

Data Register address 9C

B6

Number ofregisters

00

02






01

Protocol type 00

00

Data length 00

03


Function code 90

Data Error code 04

6.3.6 Reading Device Identifiers (0x2B)This command code allows reading identifiers and added packets that are relevantto the physical and function description of the remote devices.

Simulate the interface of the read device identifier as an address space. Thisaddress space consists of a set of addressable data elements. The data elementsare objects to be read, and the object IDs determine these data elements.

A data element consists of three objects:

1. Basic device identifier: All objects of this type are mandatory, such as thevendor name, product code, and revision version.

2. Normal device identifier: Except basic data objects, the device providesadditional and optional identifiers and data object description. Define alltypes of objects according to definitions in the standard, but the execution ofthis type of objects is optional.

3. Extended device identifier: In addition to the normal data objects, the deviceprovides additional and optional identifiers and special data objectdescription. All the data is related to the device.

Table 6-5 Reading device identifiers

Object ID Object NameorDescription

Type Mandatoryor Optional(M/O)

Type

0x00 Manufacturername

ASCIIcharacterstring

M Basic

0x01 Product code ASCIIcharacterstring

M



Object ID Object NameorDescription

Type Mandatoryor Optional(M/O)

Type

0x02 Main revisionversion


M

0x03–0x7F - - - Normal

0x80–0xFF - - - Expansion

6.3.6.1 Command for Querying Device Identifiers

Table 6-6 Request frame format


Function code 1 0x2B

MEI type 1 0x0E

ReadDevId code 1 01

Object ID 1 0x00

Table 6-7 Frame format for a normal response


Description


MEI type 1 0x0E

ReadDevId code 1 01

Consistency level 1 01

More 1 -

Next object ID 1 -

Number of objects 1 -

Object list First object Object ID 1 0x00

Object length 1 N

Object value N -

... ... ... ...



Table 6-8 Object list

Object ID Object Name orDescription

Description Type

0x00 Manufacturername

HUAWEI Basic

0x01 Product code SUN2000

0x02 Main revisionversion

ASCII characterstring, softwareversion

Table 6-9 Frame format for an abnormal response


Function code 1 0xAB


6.3.6.2 Command for Querying a Device List

Table 6-10 Request frame format



MEI type 1 0x0E

ReadDevId code 1 03

Object ID 1 byte 0x87

Table 6-11 Frame format for a normal response


Description


MEI type 1 0x0E

ReadDevId code 1 03

Consistency level 1 03

More 1 -




Description

Next object ID 1 -

Number of objects 1 -

Object list First object Object ID 1 0x87

Object length 1 N

Object value N -

... ... ... ...

Table 6-12 Object list

Object ID Object Name Type Description

0x80–0x86 Reserved -- Returns a nullobject with alength of 0.

0x87 Number ofdevices

int Returns thenumber of devicesconnected to theRS485 address.

0x88 Description aboutthe first device

ASCII characterstringSee the devicedescriptiondefinitions.

Returns onlydescription aboutthe first device ifa NE allows onlyone device to beconnected to eachRS485 address.

0x8A Description aboutthe second device

- -

- - - -

0xFF Description aboutthe 120th device

- -

6.3.6.3 Device Description Definition

Each device description consists of all "attribute=value" character strings.

"Attribute ID=%s;attribute ID=%s;... attribute ID=%s"

For example: "1=SUN2000MA-XXKTL;2=V100R001C00SPC100;3=P1.0-D5.0;4=123232323;5=1;6=1.1"



Table 6-13 Attribute definition

Attribute ID

Name Type Description

1 Device model ASCIIcharacterstring

SUN2000

2 Device softwareversion


-

3 Port protocolversion


See the interface protocol versiondefinitions.

4 ESN ASCIIcharacterstring

-

5 Device ID int 0, 1, 2, 3...(assigned by NEs; 0indicates the master device intowhich the Modbus card isinserted)

6 Feature version ASCIIcharacterstring

-

Table 6-14 Frame format for an abnormal response


Function code 1 0xAB


6.3.7 Huawei-defined Functions (0x41)

6.3.7.1 Uploading FilesUploading files means uploading them by stream data from a slave node to amaster node. The following figure shows the file uploading process.



Figure 6-8 File uploading process

6.3.7.1.1 Starting the Upload

Frame format of a request from a master node

Table 6-15 PDU data field of the request frame for starting upload (0x05)

PDUDataField

Length(Byte)

Description

Functioncode

1 0x41

Sub-functioncode

1 0x05

Datalength

1 1 + N

File type 1 Unique ID of a file

Customized data

N -



Table 6-16 PDU data field of the response frame for starting upload (0x05)

DataField

Length(Byte)

Description

Functioncode

1 0x41

Sub-functioncode

1 0x05

Datalength

1 6 + N


Filelength

4 -

Dataframelength

1 -

Customized data

N -

Table 6-17 PDU data field in the abnormal response frame of the slave node

PDU Data Field Length(Byte)

Description

Error code 1 0xC1

Exception code 1 See 6.3.2 Exception Code List.

If the exception code is 0x06, resend the request after 10 seconds. A request can be resentfor no more than six times.

6.3.7.1.2 Uploading Data

Table 6-18 Request frame for uploading data (0x06)


Description


Sub-function code 1 0x06

Data length 1 3




Description


Frame No. 2 0x0000–0xFFFF

Table 6-19 Response frame for uploading data (0x06)


Description


Sub-function code 1 0x06

Data length 1 3 + N

File type 1 -

Frame No. 2 0x0000–0xFFFF

Frame data N -

Table 6-20 Abnormal response frame for uploading data


Description

Error code 1 0xC1


6.3.7.1.3 Completing the Data Upload

Table 6-21 Request frame for completing the data upload


Description


Sub-function code 1 0x0c

Data length 1 1

File type 1 -



Table 6-22 Response frame for completing the data upload


Description


Sub-function code 1 0x0c

Data length 1 3

File type 1 -

File CRC 2 -

Table 6-23 Abnormal response frame for completing the data upload


Description

Error code 1 0xC1


6.3.7.1.4 Timeout Processing

Table 6-24 Processing specifications of sub-process timeout

Name Restraints

Response timeout period for starting anupload

10s

Response timeout period for uploading data 10s

Number of times of resending a data uploadcommand

6

Response timeout period for completing adata upload

10s



Documents

Modbus Interface Definitions (V3.0)